Blue-printing machine



Nov. 12,1929.

F. .1. TRUMPOUR 735,8l 7

BLUE PRINTING MACHINE Original Filed Jan. l0, 1927 i I 119 I t IU N yin 20 22 l 1 .1 elihilmm-IQE i i4/wwwa f J Trampozw Patented Nov. 12, 1929 l UNITED ls'raxriss PATENT OFFICE BLUE-PRINTING MAonINn Original application :Bled January 10, 1827, Serial No. 160,250, Divided and this application led August 4, 1927. `Serial No. 210,581.

The present invention relates-to improvements in blue printing machines, and constitutes a division of my prior co-pending similarly entitled application Serlal No. 160,250, filed January 10, 1927.

An object of the invention broadly 1s to provide for the application of two negatives, one at each side of a sheet of doubly sensitized blue print. paper and to expose both sides of the blue print paper through the negatives in one passage through the ma-- chine to produce economically and in a minimum of time a blue print having both its obverse and reverse faces printed. u A particular object of the present invention is to provide an assembly and feeding device in which the proper super-position of the negatives and blue print paper may be made, and in which an eifective draft of the paper-may be secured.

With the foregoing and other objects 1n view, the invention will be more fully described hereinafter, and will be more particularly pointed out 'in the claims appended hereto.

In the drawings, wherein like s mbols refer to like or corresponding parts t roughout the several views,

The figure is a vertical section taken through a blue printing machine constructed according to the present invention.

Referring more particularly to the .drawings, the broken line 10 designates the blue print paper as emerging from between .the feed rolls 11 and 12 driven by appropriate mechanism forming no part of the present invention, and consequently not shown, except that a bevel pinion 15 is designated as coupled to the shaft of the lower roll 12. This I bevel pinion 15 is in mesh with a complementary bevel pinion 16 on the vertical line shaft 17. The4 shaft 17 extends down tothe lower portion of the framework -18 of the machine where it is driven by bevel or other gears from the horizontal shaft 19 having thereon the worm wheel 2O meshing with the worm- 21 driven by the electric motor 22 or other appropriate source of power.

The rolls 11 and 12 have a peri heral movement in opposite directions, suc as to draw the blue print paper 10 through the machine.

It will be understood that a negative is placed against each side of the blue print paper, and after passing the exposure station, the defiectors 23 and 24 will separate the negatives 55 from the blue print paper, one negative being diverted to the hopper 25 and a second nega- -tive to the hopper 26.

The hoppers are located at opposite sides of the exposure station having the convex e0 glass 27. One or more lights 28 are located within or upon the concave side of the exposure glass 27; and a second source of illumination, indicated at 29, is located in spaced relation from the outside or convex surface of the exposure glass 27. A. casing 30 may be fitted about the exposure station and within the transparent traveling belt 31, which is trained over the rollers 32, 33 and 34 and is driven by the roller 35 adjacent the assembly 70 and feeding apparatus. This roller 35v is shown as placed at the initial or receivinfr end of the exposure station. The belt 31 will be of some transparent material, and the arrangement is such that one Hight of this belt will slide past the convex face of the exposure glass 27 in order to tightly press the negatv es and blue print paper thereagainst to secure that desirably great pressure necessary for good printing.y 80

Coming now to the assembly and feedin station, at 36 are indicated the upper'fee chains and at 37 the lower feed chains. The blue print or Vandyke paper 10 is shown in a roll placed in the cylindrical casing 38 lo- 85 cated between the upper and lower sets of chains P36 and 37. The blue print paper issues through an opening 39 in the .casing 38 to engage between the two negatives drawn along by the cha-ins 36 and 37. For a more 90 particular description of these chains and the registering bars by which the negatives are drawn along, reference is made to myapplication aforesaid, and also to my prior patent for blue printing machine, N o. 1,646,331, granted October 18, 1927.

It is desirable to prevent any relative creeping of the negative and blue print paper, and for this purpose the feed belt 44 is provided in conjunction with a drum 91. This upper "dicated at 46a feed belt is curved to conform generally to the curvature of the drum on'its upper run while the lower run rests upon and conforms to the curvature of the drum. The drum is preferably covered with canvas or some other appropriate material.

The chains 36 and 37 are also trained about this drum 91 and caused to follow an arcuate path about be rotated or not, as desired, but it will form a rigid backing for the lower run of the upper feed belt 44, and for the blue print paper and negatives that are passing on to the exposure station.

The rolls for supporting the belt 44a are inand 47,

surface of the by appropriate idlers 92, or by yspacing rods or other appropriate devices.

The registered negatives and blue print paper are passed over the drum 91, being ressed tightly thereagainst by the lower run of the curved belt 44a. Thereafter the superposed negatives and blue print paper are fed to the exposure station and passed between the convex side of the glass- 27 and the transparent belt 31. Thus both sides of the blue print paper are simultaneously exposed for printing from the oppositely registered negatives.

A text may be thus printed upon one side of the blue print paper, while a reference drawing may be printed upon the opposite side of the blue print paper, and thus half the filing space of such records may be saved compared with where the text is printed upon one paper and the sketch upon another paper.

Itis obvious that various changes and modifications may be made in the details of construction and design of the above specifically described embodiment of this invention without departing from the spirit thereof, such changes and modifications being restricted only by the scope of the following claims.

What is claimed is 1. A blue printing machine comprising an exposure station having an exposure glass and illuminating means on" opposite sides of the exposure glass, atransparent pressure belt moving over said exposure glass, and feeding and assembly means for supplying between said belt and glass, superposed negatives upon opposite sides blue print paper, said feeding and assembly means comprising means for marshalling the negatives upon opposite sides of the blue print paper, and pressure means for advancing the blue prlnt paper to the negatives to the exposure station, said ressure means comprising a cylinder, and a eed belt having its adjacent run lapped partially about the periphery of said cylinder, and spacing means the upper portion of the drum. The drum may The lower run of the belt will be supported upon the cylindrical" drum 9 1, while the upper run -of the belt vwill be held away from the cylinder and spacing means ""of the belt 'away from ing and assembly means comprising means I for marshalling the negatives upon opposite sides of the blue print paper, and pressure means for advancing the blue print paper and the negatives to the exposure station, said pressure means comprising a cylinder, and a feed belt having its adjacent run lapped partially about the periphery of said cylinder, for holding the other run the cylinder. 3. A blue printing machine comprising an exposure station having an exposure glass, illuminating means and a transparent pressure belt movingover said exposure glass, and feeding and assembly means for supplying between said belt and glass a negative and .sensitized blue print paper, said feeding and' assembly means comprising means for marshalling the negative and the blue print paper, and pressure means for advancing the blue print paper and negative to the exposure station, said pressure means comprising a cylinder, and a feed belt having its adjacent run lapped partially about the periphery of said cylinder, and spacing means for holding the other run of the belt away from the cylinder. i FREDERICK JAMES TRUMPOR.

of the doubly sensitized 

